Yeong Dae Kim

Treatment of mediastinitis using video-assisted thoracoscopic surgery

BACKGROUND Mediastinitis remains a life-threatening disease that is difficult to manage and has a poor prognosis. This is especially true of descending necrotizing mediastinitis, which before the 1990s era had a mortality of approximately 40% despite the use of antibiotics, surgical techniques, and intensive care monitoring. Several authors have recommended that aggressive surgical approaches for mediastinitis are more effective than simple surgical approaches; however the best surgical option for mediastinitis remains controversial. MATERIALS AND METHODS In a retrospective analysis between January 2000 and June 2006, 17 patients who underwent surgical debridement and drainage using video-assisted thoracoscopic surgery are included in this report. Data extracted from medical records included sex, age, origin of infection, surgical intervention, progress, and outcome including cause of death. There were eight men and nine women. The mean age was 52 years old (range, 20-72). RESULTS The origins of infection included esophageal perforation in nine patients and odontogenic or peritonsillar abscesses in the remaining eight patients. Among them, two patients required conversion to thoracotomy during operation in cases of mediastinitis due to esophageal perforation, so excluding the two patients, we calculated next five data for 15 patients. The mean duration from onset of symptoms to surgery was 12.4+/-13.1 days (range, 0-43) and the mean duration from the initial operation to discharge was 43.6+/-24.4 days (range, 8-113). There was serial operation in one case. There were three cases of postoperative mortality. CONCLUSION Mediastinal drainage using video-assisted thoracoscopic surgery with or without cervical drainage can be a feasible and effective surgical option. This less invasive technique seems to have an outcome similar to more aggressive open surgical approaches for patients with mediastinitis previously reported in the literature, although it has not been directly compared.

Periostin mediates human adipose tissue-derived mesenchymal stem cell-stimulated tumor growth in a xenograft lung adenocarcinoma model.

Mesenchymal stem cells stimulate tumor growth in vivo through a lysophosphatidic acid (LPA)-dependent mechanism. However, the molecular mechanism by which mesenchymal stem cells stimulate tumorigenesis is largely elusive. In the present study, we demonstrate that conditioned medium from A549 human lung adenocarcinoma cells (A549 CM) induces expression of periostin, an extracellular matrix protein, in human adipose tissue-derived mesenchymal stem cells (hASCs). A549 CM-stimulated periostin expression was abrogated by pretreatment of hASCs with the LPA receptor 1 (LPA(1)) inhibitor Ki16425 or short hairpin RNA-mediated silencing of LPA(1), suggesting a key role of the LPA-LPA(1) signaling axis in A549 CM-stimulated periostin expression. Using a xenograft transplantation model of A549 cells, we demonstrated that co-injection of hASCs potentiated tumor growth of A549 cells in vivo and that co-transplanted hASCs expressed not only periostin but also α-smooth muscle actin (α-SMA), a marker of carcinoma-associated fibroblasts. Small interfering RNA- or short hairpin RNA-mediated silencing of periostin resulted in blockade of LPA-induced α-SMA expression in hASCs. In addition, silencing of periostin resulted in blockade of hASC-stimulated growth of A549 xenograft tumors and in vivo differentiation of transplanted hASCs to α-SMA-positive carcinoma-associated fibroblasts. Conditioned medium derived from LPA-treated hASCs (LPA CM) potentiated proliferation and adhesion of A549 cells and short interfering RNA-mediated silencing or immunodepletion of periostin from LPA CM abrogated proliferation and adhesion of A549 cells. These results suggest a pivotal role for hASC-secreted periostin in growth of A549 xenograft tumors within the tumor microenvironment.

Localization of pulmonary nodules with lipiodol prior to thoracoscopic surgery

Background Preoperative localization with lipiodol for identifying small or deeply seated pulmonary nodules is simple and useful for thoracoscopic surgery. Although several studies about performance and complication rates of lipiodol localization have been reported, there has been no report about the performance and complication rates of lipiodol localization with regard to the CT appearance of pulmonary nodules. Purpose To evaluate the performance and complication rates of localization of pulmonary nodules with lipiodol prior to video-assisted thoracoscopic surgery with regard to the CT appearance of nodules. Material and Methods After institutional review board approval and informed consent were obtained, lipiodol marking was performed in 67 patients (33 men and 34 women; mean age 58 years) with 68 nodules. All nodules were marked with 0.4–0.5 mL lipiodol under CT guidance on the day of surgery. The size of the targeted nodule and the shortest distance to the accessible pleural surface were measured. Lipiodol accumulation of a targeted nodule was scored by use of a four-point scale (0: none, 1: within 1 cm around a nodule, 2: partial accumulation within a nodule, 3: total accumulation within a nodule). Any complications after localization of nodules were noted. We analyzed the score of lipiodol accumulation and the presence of complications for the CT appearance of pulmonary nodules using the Mann Whitney U test, Fishers exact test and the Kruskall Walis test. Results The average nodule size was 11.4 mm (range 3.0–28.3 mm) and the average distance to the pleural surface was 13.7 mm (range 0–51.4 mm). Lipiodol accumulation scores of nodules were as follows: score 3 (n = 19, 28%), score 2 (n = 37, 54%), score 1 (n = 11, 16%), and score 0 (n = 1, 2%). Lipiodol accumulation scores of nodules were different according to the size of nodules (Kruskal Wallis test, p = 0.023). Pneumothorax after localization occurred in 20 (29%) patients and the incidence was higher in nodules located in the subpleural area (Mann Whitney U test, p = 0.048). Pulmonary hemorrhage along the needle tract occurred in five (7%) patients and was more frequent in patients with deep nodules as compared to shallow nodules (Mann Whitney U test, p < 0.001). Conclusion Lipiodol marking under CT guidance is a useful and safe procedure for the intraoperative localization of pulmonary nodules. Of variable CT findings, lesion size is important to determine the degree of lipiodol accumulation and the lesion depth is the most important feature for the development of postprocedural complications.

IS6110-Restriction Fragment Length Polymorphism and Spoligotyping Analysis of Mycobacterium tuberculosis Clinical Isolates for Investigating Epidemiologic Distribution in Korea

The Beijing family of Mycobacterium tuberculosis has been emerging in the world. However, there are few nationwide data of genotypic distribution in Korea. This study aimed to identify the genotypic diversity of clinical isolates of M. tuberculosis and to demonstrate the population of Beijing family in Korea. We collected 96 clinical M. tuberculosis isolates from 11 university hospitals nationwide in Korea from 2008 to 2009. We observed 24 clusters in IS6110-RFLP analysis and 19 patterns in spoligotyping. Seventy-five isolates were confirmed to be Beijing family. Two isolates of the K strain and 12 isolates of the K family strain were also found. We found that drug resistance phenotypes were more strongly associated with Beijing family than non-Beijing family (P=0.003). This study gives an overview of the distribution of genotypes of M. tuberculosis in Korea. These findings indicate that we have to pay more attention to control of M. tuberculosis strains associated with the Beijing family.

Primary Alveolar Soft Part Sarcoma of the Lung

Alveolar soft part sarcoma (ASPS) is a rare epithelial-like soft tissue sarcoma. The two main sites of its occurrence are the lower extremities in adults and the head and neck in children. Primary pulmonary involvement of this sarcoma, without evidence of soft tissue tumor elsewhere, is very exceptional. We present a case of primary ASPS of the lung in a 42-yr-old woman. A computed tomographic scan of the thorax demonstrated a well-circumscribed, solid tumor located in the right upper lobe. The mass was resected by right upper lobectomy. After 5 months, three metastatic lesions, involving lumbar vertebrae and occipital scalp, were found. Histologically, the tumor consisted of alveolar nests of large polygonal tumor cells, the cytoplasm of which frequently revealed periodic acid-Schiff-positive, diastase-resistant intracytoplasmic rod-like structures. On immunohistochemical staining, the tumor cells were positive only for vimentin and alpha-smooth muscle actin. Ultrastuctural study using electron microscopy revealed characteristic electron-dense, rhomboid intracytoplasmic crystals.

Imaging Findings of Primary Multidrug-Resistant Tuberculosis: A Comparison With Findings of Drug-Sensitive Tuberculosis

Objective: This study was designed to identify and describe thin-section computed tomographic (CT) findings of primary multidrug-resistant tuberculosis (MDR TB) as compared with the findings for drug-sensitive TB. Methods: Between October 2002 and December 2007, thin-section chest CT findings of 39 patients with primary MDR TB and 39 patients with drug-sensitive TB were retrospectively reviewed. The frequency and patterns of lung lesions (including centrilobular nodules, large nodules, consolidation, cavity, fibrotic bands, bronchiectasis, calcification, pleural effusion, lymphadenopathy, number of lobes affected by parenchymal lesions, and laterality) were compared. Statistical comparisons were performed with the use of the &khgr;2 and the Mann-Whitney U tests for univariate analysis, and a stepwise logistic regression method was used for multivariate analysis. Results: Based on univariate analysis, bilateral involvement (P < 0.001), segmental or lobar consolidation (P < 0.001), and cavities (P < 0.001) were more frequently seen in primary MDR TB patients. A stepwise logistic regression analysis demonstrated that bilateral involvement of parenchymal lesions (odds ratio, 4.7; 95% confidence interval, 1.4-15.6; P = 0.012) and multiple cavities (odds ratio, 1.7; 95% confidence interval, 1.2-2.5; P = 0.004) were significant CT findings associated with primary MDR TB. Conclusions: The presence of primary MDR TB as detected on a CT scan may help the use of appropriate therapy for infected patients before obtaining a definite diagnosis based on bacteriology.

One-stage Laparoscopic Repair of Morgagni and Inguinal Hernias in a Two-month Old Male

The development of Morgagni hernias is related to malformations of the embryologic septum transversum after failure of the sternal and costal fibrotendinous elements of the diaphragm to fuse. The overall incidence of Morgagni hernias among all congenital diaphragmatic defects is 3% to 4%. Inguinal hernias are the most common hernias in males and females (25% and 2%, respectively). An inguinal hernia is defined as a protrusion of the abdominal cavity contents through the inguinal canal. The combination of Morgagni and inguinal hernias is rare, and treatment using laparoscopic surgery has not been previously reported. This case presents a one-stage laparoscopic repair of Morgagni and inguinal hernias in a 2-month-old male.

Direct lipiodol injection used for a radio-opaque lung marker: stability and histopathologic effects

ABSTRACT The objective of this study was to evaluate the effects on the histopathologic findings of directly injected lipiodol into lung and to identify the existence of remaining lipiodol in the lung according to the follow-up time. Forty rats were randomly assigned to 1 of 4 groups: group I (n = 10) served as the control group and received 0.2 mL of normal saline; groups II (n = 10), III (n = 10), and IV (n = 10) served as experimental groups and received 0.1–0.2 mL of lipiodol under fluoroscopy. At 3 hours (groups I and II), 24 hours (group III), and 1 week (group IV) after injection, the radiographic presence of lipiodol and histopathologic findings of each group were evaluated. Minimal acute lung injuries developed and the radio-opaque lipiodol nodule remained in group II. In group III, acute lung injuries were the most serious. However, acute injuries disappeared and foamy macrophages accumulated within the alveolar space in group IV. In this group, remaining lipiodol was also identified on radiograph. Directly injected lipiodol caused acute lung injury, which disappeared at 1 week along with the resolving process. On radiographs, directly injected lipiodol remained after 1 week. Lipiodol could be used as a safe and stable biomaterial for marking pulmonary nodules.

The Feasibility of Extracorporeal Membrane Oxygenation in the Variant Airway Problems

INTRODUCTION Extracorporeal membrane oxygenation (ECMO) is widely used to treat respiratory distress during cardiac or respiratory arrest; moreover, its use is being extended to a wide variety of clinical fields. In this study we assess the utility of ECMO in the management of airway obstruction. PATIENTS AND METHODS 15 patients underwent ECMO for airway obstruction. We retrospectively analyzed and evaluated the feasibility of ECMO in the treatment of airway problems. RESULTS Seven patients received ECMO to facilitate respiration and promote stability during trachea surgery. In six cases ECMO ceased immediately following the operation; in the remaining case ECMO cessation was delayed due to post-operative ARDS. In three cases emergency ECMO was used in response to respiratory arrest; two patients died. In five cases ECMO was emergently inserted to prevent death, following airway blockade by massive hemoptysis. One patient was not discharged from the intensive care unit. Another patient was transferred to a general ward but died from other causes. CONCLUSION ECMO is useful during anesthesia in patients at high risk of airway blockade, for example due to endobronchial bleeding, and during complex thoracic surgery. ECMO confers a safer environment during airway surgery, and its complication rate is acceptable.

Characteristics of Molecular Strain Typing of Mycobacterium tuberculosis Isolated from Korea

Molecular strain typing of Mycobacterium tuberculosis is important for the detection of outbreaks of tuberculosis and laboratory cross contamination, as well as the differentiation between re-infection and reactivation of tuberculosis. In the present review, the authors investigated the currently available typing methods for M. tuberculosis and the current status of strain distribution in Korea. IS6110-restriction fragment length polymorphism (RFLP), which is considered a standard method, is based on numbers and positions of the insertion sequence, IS6110. The method has an excellent discriminatory power with a considerable amount of worldwide data, although it is time-consuming and labor-intensive. Spoligotyping is based on the presence or absence of spacer sequences between direct repeat (DR) regions. PCR amplification allows for the possibility of application in the early suspicious stage. The data can be easily digitized; however, it shows identical profiles in Beijing family strains. Mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRUVNTR) is another PCR-based genotyping method with a good discrimination power whose data can also be easily digitized. In Korea, the prevalence of Beijing family strains have been as high as 80 to 87%. (Korean J Clin Microbiol 2011;14:41-47)